Autonomic neuropathy in Type 2 diabetic patients is associated with hyperinsulinaemia and hypertriglyceridaemia

Aims. To clarify whether parasympathetic neuropathy in Type 2 diabetic patients is associated with features of the insulin resistance syndrome. Methods. Blood pressures, glycaemic control (HbA(1C)), plasma lipids, residual P-cell function (fasting plasma C-peptide), autonomic nerve function, urinary albumin excretion and glomerular filtration rate (Cr-EDTA clearance) were evaluated in 82 Type 2 diabetic patients (age 61 +/- 1 years) 5 years after diagnosis of diabetes. Results. Parasympathetic neuropathy (an abnormal age corrected E/I ratio) was found in 24/82 (29%) patients. After adjustment for body mass index (BMI), patients with parasympathetic neuropathy had elevated fasting plasma C-peptide (P < 0.001) and triglyceride (Tg) (P < 0.005) levels compared with patients without parasympathetic neuropathy. In addition, the age corrected E/I ratio correlated inversely with Tg (r = -0.31; P < 0.01) and fasting plasma C-peptide (r = -0.32; P < 0.001) in the Type 2 diabetic patients. Conclusion. Autonomic neuropathy 5 years after diagnosis of Type 2 diabetes is associated with an unfavourable metabolic risk profile.